1. Field of the Invention
The present invention relates to a display method and a device thereof. More particularly, the present invention relates to a display method with interlacing reversal scan and a device thereof.
2. Description of Related Art
In recent years, flat panel displays are developed rapidly owing to mature photoelectric technology and semiconductor manufacturing technology. Liquid crystal displays (LCD) advantageous in low-voltage operation, no-radiation, lightness, and small volume have gradually replaced conventional cathode-ray tube (CRT) displays and become a mainstream produce in the market.
An LCD mainly includes a liquid crystal panel and a backlight module. As the liquid crystal which is injected into the liquid crystal panel does not emit light itself, the liquid crystal panel must be illuminated by a surface light source provided by the backlight module, so that the LCD can display.
The color display mixing can be classified into a temporal color mixing and a spatial color mixing methods. For the color display mixing of a display, currently, spatial with additive color mixing is generally applied to a display. Taking thin-film transistor LCD (TFT-LCD) for example, each pixel which is composed of three sub-pixels of red, green, blue (RGB) distributed on a color filter, and when the sub-pixels are small beyond the distinguishable viewing angle of human eyes, a color mixing effect is observed by visual perception.
If the spatial color mixing of the TFT-LCD is replaced by a temporal color mixing, the color filter is not used for achieving the color mixing effect, the backlight source is directly used with relative data display to achieve the temporal color mixing effect, thereby increasing the transmission rate of the module and saving the overall manufacturing cost of the module.
FIG. 1 is an architectural diagram of a driving circuit of a conventional field sequential display (FSD). Referring to FIG. 1, an FSD controller 103 is used to convert spatial parallel RGB video data at a system of a video source 101 into temporal serial R→G→B video data and then output it. As the video data is enormous in quantity, a frame memory 107 and the FSD controller 103 must be used, and a backlight module 105 is controlled in sync during the converting process, such that according to different primary color data to be displayed, a corresponding light source is lightened to make a panel module 109 to display a video image.
FIG. 2 is a conventional FSD driving waveform diagram. Referring to FIG. 2, in order to preventing a false color mixing when the RGB data is written through scanning, the backlight module 105 is turned on or off according to data scanning. When the data is written, the light source of the backlight module 105 is turned off. After the data is written, the light source of the backlight module 105 is turned on, so as to achieve the temporal color mixing of the RGB and to prevent the occurrence of false color mixing.
FIG. 3 is a luminance response diagram of a conventional FSD. Referring to FIG. 3, as the color sequential method has shortened a response time of the liquid crystal, the sequence of the address data is more sensitive than the conventional LCD. Referring to FIG. 3, it can be found that the time from the originally written data (the first several scan lines) to the light source of the backlight module 105, being turned on, is relatively long, i.e., the response time of the liquid crystal is relatively long. Therefore, when the light source of the backlight module 105 is turned on, the luminance response of the liquid crystal can reach a set value. Said time from the last written data (last several scan lines) to the light source of the backlight module 105, being turned on, is relatively short. Thus, the time for the liquid crystal luminance response to reach a set value is not enough and then the color distribution between the up-side and the down-side region of the entire frame may be uneven. In the conventional art, for example, Japanese Laid-Open Patent Application No. 2001-318363, relating to color sequential method, does not provide a solution to this problem.
FIG. 4 is a conventional double frequency FSD response diagram. Referring to FIG. 4, currently, there are two methods for balancing the color distribution between the up-side and the down-side region. When the first method is used, the driving frequency is increased to double the conventional one. Therefore, the response time of each pixel can be made consistent. However, when the driving frequency is doubled, the hardware performance is required to be enhanced, thus increasing the cost of the hardware.
FIGS. 5A and 5B are diagrams of a conventional reversal scan mode. FIGS. 6A and 6B are response diagrams of transmission rate of the conventional reversal scan mode in FIGS. 5A and 5B. Referring to FIGS. 5A, 5B, 6A, and 6B, the scanning sequence is achieved in a reversal manner. Thus, each color frame with poor luminance response can be alternately distributed on the up-side and the down-side region of the frame instead of being concentrated on the low-side region. As such, during the continuous frame displaying period, the present invention may balance color distribution between the up-side and the down-side region. However, another serious problem may exist. If the luminance difference between the up-side and the down-side region is too great, the flicker phenomenon in a large scope is easily generated when there is no balanced effect in space.
It may be clearly observed from the above description that the problem of uneven color distribution between the up-side and the down-side region exists the conventional art. If the problem is solved by increasing the operating frequency, the hardware cost will be increased. Further, if the problem is solved by reversal scan mode, a serious flicker phenomenon is incurred.
In view of the above, panel manufacturers are in urgent need of a proper solution to solve the aforementioned problems.